This invention pertains to waste processing, and more particularly to apparatus for treating and disposing of spent photographic fixer and developer chemicals and removing silver therefrom.
The present invention is a further development of the effluent precipitation and neutralization chamber described in Woog, U.S. Pat. Nos. 4,608,177 and 5,132,022. In these apparatus of these patents, spent photographic fixer and spent photographic developer are mixed together in a closed chamber. To assure proper mixing of the spent fixer and developer, the fluid flow paths within the chambers included baffles and materials such as plastic ribbons that caused the fluids to flow in a tortuous path. The spent fixer, which is normally acidic in nature, having a pH of about 4.5, is neutralized by the alkaline developer, which normally has a pH of about 10.5. As a result, iron in the fixer in the form of ferrous oxide is precipitated as fine particles, and a relatively neutral and clear liquid is discharged from the chamber to a drain. The iron precipitate is periodically cleaned from the chamber for proper disposal.
This invention relates to improvements over the apparatus set forth above and to solutions to the problems raised or not solved thereby.